A long standing problem in the production, handling, storage and transportation of crude oil is the depositing out of hydrocarbons on the surfaces of such equipment. These hydrocarbons are dissolved in the crude oil at the comparatively high temperatures of underground formations but are insoluble to varying degrees at the temperatures at which most production, handling, storage and transfer equipment are maintained. The accumulation of these hydrocarbons, such as waxes, asphaltenes and resins, (herein collectively referred to as paraffins) can restrict the flow of oil through the equipment and ultimately result in partial or complete plugging. For example, as crude oil is pumped from a production well through production tubing, paraffins deposit on the inner surface of such tubing as the crude oil cools. Similarly, in the transport of crude oils containing soluble paraffins, flow in pipe lines can be restricted by the deposition of these paraffins as the crude oil cools during transport.
Several methods have been used to remove these paraffin deposits including mechanically scraping the equipment surfaces, contacting the paraffin deposits with various organic solvent systems and the application of hot oils or external heat.
Systems have also been used to further inhibit such deposits such as incorporating crystallization modifiers or flow promoters into the crude oil or the application of a magnetic field.